A knee airbag apparatus protects legs of a passenger upon a collision by deploying an airbag between an instrument panel and the lower legs, for example, tibias of the passenger.
The airbag prevents a passenger from colliding with the instrument panel at a high acceleration upon a vehicle collision. The instrument panel is made of a high stiffness material so a high force is applied to the legs of the passenger when the passenger collides with the instrument panel at a high acceleration.
The airbag allows the passenger to collide with the airbag instead of the components of a vehicle, so that relatively low impact is applied to the passenger.
The knee airbag apparatus, which is located behind the instrument panel, is configured to be deployed through a door or chute placed on a surface of the instrument panel.
To the contrary, the knee airbag apparatus, which is installed at a low portion of the instrument panel, is deployed toward the bottom of the vehicle at the first stage, and then, is deployed upward along the instrument panel of the vehicle (this knee airbag apparatus is called a low mounting knee airbag apparatus).
Thus, the study and research have been performed on various deployment paths of the knee airbag apparatus for effectively deploying the airbag of the knee airbag apparatus toward an upper portion of a vehicle along a shape of an instrument panel.
(Patent document 1) U.S. Patent publication No. 2012/0025498 A1